Ok well I have installed this bov on other cars I have owned(I have owned 6 turbo cars) with no problems. Im not a newbie who know nothing about turbo but Im not a guru either. I installed the hKS BOV and I also have the aem intake and grounding kit. It is vented to the atmostphere(have the recirculate hole pluged) and I have spring set pretty stiff(not quite all the way to the tense side but pretty close). also installed everything that came with my hks including the vacuum line adapter that makes the line small to the actual bov. I have this problem when I let off and the car blows off if I dont engage another gear and just let the idle drop it goes past 800 all the way to about 400 and almost dies but then raises back to 800 and is steady. This is the only time this happens and it doesnt matter what gear Im in or how fast im going. Ig I shift into the next gear this obviously doesnt happen because the rpms stay up because of the gear thats engaged. Any help would be great guys. Thanks

 

Have you ever used the HKS SSQV or any other VTA valves on your other turbo cars? This sounds normal for a VTA valve on the EVO.

 

Little have had luck with the SSQV on the EVO, either re-circ or vta

I had the same issue while recircing the ssqv, and then tried using my S-AFCII to help out the idle issue and also eids..

With no luck, I pushed on and tried the type-r greddy bov, which comes set-up only for re-circ. Have had no problems thus far, and my idle is smooth once again....

Sell the ssqv...

 

Huh do you think its the specific bov itself or the car that wont work with it?

 

same here, i used this bov on my eclipse turbo and even 300zx TT, no problem, but on evo, there is rpm drop issue, ive tested and i didn't like it, - i bought REC KIT, ok seems better but still rpms drop, i would prefer the stock bov over shks... (evo hates venting)

 

95% of the people who use SSQV VTA on the EVO have the exact same problem as you are or even worse. The car just does not like them.They spit ,studder and idle like crap. Do a search and you will see many identical threads to this one. The Greddy seems to work well, like others have stated.

Theres a great write-up on BOV's on the front page, you may be interested in.

 

Greddy type S recirculated, take out the smaller spring, adjust a little bit stiff, then ready to go. Idle is smooth.

 

i had problems, then i put in my stock bov

 

Well with the boost Ill be running in a few weeks the stock bov is not an option.